Gender and fat loss

Overview: There are many reported anecdotes of husbands and wives going on an exercise program together and the husband losing significantly more weight than the wife. But does research support the notion that men and women’s body fat responds to exercise differently? If so, are there gender-based mechanisms to explain why women are different from men? This is important to establish because if women have greater trouble losing fat they are likely to need female-specific fat loss programs.

Do women lose less fat after exercise compared to men?: There is surprisingly little research into this topic. However, some well controlled studies have shown that women do lose significantly less fat when engaging in exercise-based fat loss programs compared to males. For example, Donnelly et al. (2002) carried out a 16-month exercise intervention in overweight males and females aged 17-30 years. They found that the men lost on average 5.2 kg of weight compared to no decrease in the women. A small number of other studies have reported similar findings. Mechanisms underlying gender differences are complex and include the following: differences in body fat distribution, smaller energy expenditure of exercise, greater energy intake, fat oxidation patterns, and societal forces.

Gender differences in body fat distribution: Females have a gynoid whereas males typically have a android fat distribution. Thus, females have fat stores on their hips, legs, and upper arms, whereas males concentrate their fat around their abdomen. Fat content for men is about 12-24% and for women about 15-35%. Women need to store extra fat to help with pregnancy. Female fat stores are generally in smaller fat cells around the hips. In contrast, men have larger fat cells around their abdomen.

Energy expenditure of exercise and compensatory intake: There is some evidence to suggest that compared to men, women have a smaller energy expenditure to exercise. Because women typically have less muscle than men the energy used up in exercise is significantly less for women of the same weight. Also research has shown that some women tend to increase their energy intake (eat more) after exercise more so than men. Other research has shown that men generally put on weight through ignorance of basic nutrition, whereas women tend to put on weight more because they use food as a strategy to cope with life’s stressors. Cortisol is a major stress hormone and has been shown to induce the body to store rather than burn fat. So gender difference in cortisol levels may have an influence.

Fat oxidation patterns: It also appears that for the same amount of physical effort women burn less fat than men. Gender difference in fat utilization, however, is a controversial area. Other hormonal gender differences may involve thyroid. Low thyroid activity is a major impediment to fat loss and Australian women have more thyroid problems than men.

Summary: It seems that men can perform more vigorous exercise which may be more conducive in reducing abdominal fat. Women are disadvantaged by their smaller muscle mass and larger fat mass. Also women, generally, may possess greater problems with a sluggish thyroid gland. Recently, we have shown that women can lose significant amount of fat using intermittent sprinting exercise. Thus, the 8/12 second lifesprint protocol may be powerful enough to induce significant fat loss in women.

Males naturally have more muscle than woman, the more muscle you have, the faster you lose weight. That is why it is important to include stregth training in a workout if you are trying to lose weight. you want to build muscle because it burns more calories than fat, so at rest you will be burning more calories. so all in all, men have more muscle than women so they burn more calories at rest, so they lose weight faster have a nice day!

mmm sprinting. I can't remember when I was more in shape than when I was doing the 40 yd dash in Track....

so does this mean we have to cut back even more than is suggested in the intake dept? I thought that slowed your metabolism down.

For me its like a catch 22. I can't lose enough weight because I dont have enough muscle. And I can't get enough muscle tissue because I can't get rid of the excess weight.

i was also told that eating after exercise IS better because your metabolism is higher then, so its a better time to eat.

I used to not eat before and after exercise but now I do both and I have seen a bigger difference in muscle gain. I feel better when I eat before and after, and this helps prevent muscle breakdown as well. Your body will use the nutrients from foods around this time. The only time I may not eat around a workout is for a quick steady state cardio session so I dont feel heavy. Any interval or weight training I make sure I eat.